miR-181 regulation of BAX controls cisplatin sensitivity of prostate cancer cells.

Prostate cancer is one of the most common male malignancies and remains the second leading cause for cancer-specific mortalities in men. Cisplatin is commonly used as a chemotherapeutic agent against advanced cancers, and is now used in metastatic prostate cancers. Cisplatin exerts its cytotoxic effects by cross-linking genomic DNA (gDNA) which induces DNA damage on rapidly dividing cancer cells. However, cisplatin leads to systemic side effects and some patients never respond. Our previous report demonstrated an oncogenic role of miR-181a in human prostate cancer. In this study, we investigate the mechanistic potential of miR-181a in regulating cisplatin sensitivity in this context. We report that cisplatin treatment significantly enhanced miR-181a expression and that exogenous overexpression of miR-181a decreased sensitivity of prostate cancer cells to cisplatin. Additionally, we observed that cisplatin-resistant prostate cancer cells harbored high levels of miR-181a expression. Mechanistically, we demonstrate the pro-apoptotic protein, BAX, is typically enhanced by cisplatin treatment but its suppression promoted resistance. Here we demonstrate miR-181a regulation of BAX was mediated through a complimentary interaction with the 3'UTR of the BAX transcript. We subsequently show that BAX expression restored cisplatin sensitivity in miR-181a overexpressing prostate cancer cells. In parallel, we demonstrate inhibition of miR-181a restored BAX expression as well as cisplatin sensitivity in resistant cells. This study suggests that miR-181a is a potential therapeutic target for prostate cancers that are resistant to cisplatin.

Cullin-1 promotes cell proliferation via cell cycle regulation and is a novel in prostate cancer.

BACKGROUND: There is no reliable marker available for early detection, diagnostic confirmation, or disease prognosis available of prostate cancer (PCa). We aimed to evaluate the function of Cullin-1 and unravel its underlying molecular mechanism to develop novel treatment options equivalent to PCa. METHOD: We used immunohistochemistry to analyze the correlation between Cullin-1 expression and clinicopathologic variables and patient survival. The Cullin-1 level was tested in PCa cells. The role of regulation of Cullin-1 in PCa was applied in vitro and vivo. In addition, we further investigated the signaling pathway of Cullin-1 in prostate cancer cell proliferation. RESULT: We first discovered that Cullin-1 expression was upregulated in human PCa tissues and inversely related with PCa differentiation. We then found that high expression of Cullin-1 protein suggested a poor prognosis in PCa patients. Also, Cullin-1 promotes PCa cell proliferation in vitro and tumor growth in vivo. We then found that the mechanism of Cullin-1 regulation on cell-cycle progression is due to increased expression of p21 and p27, and decreased expression of cyclin D1 and cyclin E after Cullin-1 knockdown. CONCLUSION: Cullin-1 exerts multiple biological effects in the PCa cell line. Through promoting proliferation and by countering cisplatin-induced apoptosis, Cullin-1 has been deeply implicated in the pathogenesis and development of PCa.

Over-expression of lipocalin 2 promotes cell migration and invasion through activating ERK signaling to increase SLUG expression in prostate cancer.

BACKGROUND: Metastasis is the primary cause of prostate cancer (PCa) lethality and poses a huge clinical obstacle. Lipocalin 2 (LCN2), a member of the lipocalin family, is aberrantly expressed in some human cancers and has been implicated in the progression of some tumors. However, the role of LCN2 in the metastatic capacity of prostate cancer (PCa) is poorly understood. METHODS: LCN2 expression was examined by RT-qPCR and/or immunoblotting in human prostate tissue specimens and prostate cancer cell lines LNCaP, C4-2, 22RV1, PC3, DU-145, and PC3MM2. LCN2 protein level in human serum samples was determined by ELISA. Lentiviruses-mediated over-expression of LCN2 and knockdown of LCN2 was conducted to evaluate the role of LCN2 in cell migratory and invasive capacities of prostate cancer cells. Cell migration and invasion was examined by transwell chamber assay. Knockdown of SLUG by lentivirus was performed to investigate its role in LCN2-promoted cell migration and invasion in vitro (22RV1 cell line) and metastasis in vivo (tail vein metastasis assay in nude mice). Role of ERK signaling in LCN2-mediated up-regulation of SLUG was assayed by using ERK inhibitor U0126. RESULTS: We confirmed that LCN2 levels were correlated positively with invasive prostate cancer in human tissue and serum samples, and were also consistently associated with the invasive capacity of prostate cancer cell lines. The over-expression of LCN2 in 22RV1 cells (not highly invasive) promoted the epithelial-mesenchymal transition (EMT), increasing cell motility and invasiveness, while the knockdown of LCN2 in PC3 cells (highly invasive) inhibited EMT, decreasing cell motility and invasiveness. Among the multiple EMT transcription factors, LCN2 specifically induces the expression of SLUG, which was shown here to be required for the LCN2-induced increase in the invasive capacity of prostate cancer cells both in vitro and in vivo. Mechanistically, LCN2 promoted SLUG expression via activating ERK signaling pathway. CONCLUSION: LCN2 plays an important role in promoting cell migration and invasion of prostate cancer by inducing EMT through the ERK/SLUG axis. Therefore, targeted inhibition of LCN2 may represent a therapeutic strategy to prevent the metastasis of prostate cancer.

Farnesoid X receptor inhibits LNcaP cell proliferation via the upregulation of PTEN.

Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. In the present study, the activation of the farnesoid X receptor (FXR), a member of the nuclear receptor superfamily, was demonstrated to inhibit cell proliferation in LNcaP cells. Using clinical samples, mRNA and protein levels of FXR were found to be significantly decreased by quantitative PCR and western blot analysis in prostate cancer tissues. In vitro studies identified further that activation or overexpression of FXR suppressed prostate cancer cell proliferation as measured by BrdU incorporation assays. At the molecular level, the results further revealed that the expression of the tumor suppressor gene, PTEN, was upregulated by FXR activation. Therefore, the observations indicated that FXR functions as a tumor suppressor in prostate cancer, which may provide a novel method for molecular targeting cancer treatment.

microRNA-181 promotes prostate cancer cell proliferation by regulating DAX-1 expression.

microRNAs (miRNAs) are a class of short noncoding RNA molecules that have a critical role in the initiation and progression of types of human cancer, including prostate cancer. In the present study, the expression of miR-181 in prostate cancer tissues was evaluated and was demonstrated to be significantly upregulated in prostate cancer tissues compared with that in adjacent normal tissues. The results of in vitro MTT and BrdU incorporation assays, as well as cell-cycle analysis, indicated that miR-181 overexpression markedly promoted the proliferation of LNCaP cells. Furthermore, miR-181 overexpression was found to promote the progression of LNCaP tumor growth in nude mice. Mechanistic studies demonstrated that dosage-sensitive sex reversal, adrenal hypoplasia critical region, on chromosome X, gene 1 (DAX-1), a negative regulator of androgen receptor in prostate cancer, was inhibited by miR-181 overexpression. Therefore, the results from the present study suggest that miR-181 functions as a growth-suppressive miRNA during prostate cancer development.

Adrenal ganglioneuromas: experience from a retrospective study in a Chinese population.

PURPOSE: Ganglioneuromas (GNs) are benign neoplasms of combined neural crest, schwannian,and connective tissue origin, occurring rarely in the adrenal glands. The present study is to share our experience regarding diagnostic and therapeutic management of these tumors. MATERIALS AND METHODS: Adrenal GNs of 15 patients were found incidentally with ultrasonography and were evaluated subsequently with computed tomography (CT) scan. Clinical data as well as follow-up data were collected retrospectively. All the patients received operative resection. RESULTS: The mean age of the patients was 38.4 years (range, 25-52 years; male to female ratio, 2:1). Of study subjects 11 patients had unilateral GN on the right side, and the remaining 4 on the left side. All but 1 patient were asymptomatic. No hormonal secretion was apparent. Mean size of the tumors in CT scan was 6.27 cm (range, 2.5-14 cm), while 10 were larger than 5 cm. Eight patients underwent open adrenalectomy and the remaining 7 underwent laparoscopic anterior adrenalectomy. Histologically, all 15 neoplasms were completely differentiated,mature GN. We had no mortality or significant morbidity. Mean duration of hospitalization was 5.5 days (range, 3-7 days). There was no recurrence, during a mean followup of 5.4 years (range, 1-10 years). CONCLUSION: Pre-operative diagnosis of adrenal GNs remains difficult merely according to physical examination. Therefore, we recommend complete operative resection once malignancy cannot be excluded by pre-operative analyses. Laparoscopic adrenalectomy is a reasonable option, at least for tumors ≤ 5 cm.

A comparison of laparoscopic and abdominal radical parametrectomy for cervical or vaginal apex carcinoma and stage II endometrial cancer after hysterectomy.

BACKGROUND AND OBJECTIVE: Radical parametrectomy (RP), performed either abdominally (ARP) or laparoscopically (LRP), is a viable alternative to radiotherapy in treating invasive cervical cancer, vaginal apex cancer, and endometrial cancer that is more advanced than initially suspected after hysterectomy. We carried out a comparative study on intra- and postoperative parameters between the two performed by similarly experienced surgeons. METHODS: Forty consecutive patients indicative for RP were reviewed: 22 and 18 underwent ARP and LRP, respectively. Information was collected on demographics, indications for initial and this surgery, tumor characteristics, intra- and postoperative parameters, and complications. The lengths of resected parametrial and vaginal tissues were measured. RESULTS: Compared with ARP, LRP resulted in shorter operative time (200 vs 239 min), less blood loss (627.8 vs 929.5 mL), shorter hospital stay (16.8 vs 19.9 days), and removal of more pelvic lymph nodes (27.4 ± 5.9 vs 23.1 ± 7.1). Although it was not attempted in ARP to remove lymph nodes in the deep obturator space, it was attempted in LRP and one positive node was found. In the ARP cohort there was one case of injury to the small intestine during surgery, whereas in LRP there was one instance of lower urologic fistula after surgery. CONCLUSION: LRP is superior to ARP in terms of shorter operative time, less blood loss, and shorter hospital stay while still maintaining the completeness of the procedure. It can be safely performed in the hands of experienced surgeons for cervical or vaginal apex carcinoma and stage II endometrial cancer after hysterectomy.

Association between promoters polymorphisms of matrix metalloproteinases and risk of digestive cancers: a meta-analysis.

PURPOSE: A variety of studies have been performed to elucidate the polymorphisms in promoter regions of matrix metalloproteinases (MMPs) associated with the risk of digestive cancers, and yet, results remain conflicting and heterogeneous. Thus, we undertook a systematic meta-analysis to determine the genetic susceptibility of MMPs to digestive cancers. METHODS: A computerized literature search was conducted in databases of PubMed, Embase, and ISI Web of Knowledge till October 2012 for any MMP genetic association study in oral squamous, gastric, esophageal, and colorectal carcinomas. Odds ratios (OR) and 95 % confidence interval (CI) were estimated for each gene under dominant and recessive models, and the heterogeneity between studies was assessed using Q test and I (2) value. Overall and subgroup analysis according to anatomical sites and ethnicity was carried out. Statistical analysis was performed with Review Manager 5.0. RESULTS: A total of 40 eligible publications with 68 comparisons were included in this study. For MMP1 nt-1607, individuals with 2G state could increase risk of digestive cancers in total analysis (dominant: OR = 1.31, 95 % CI = 1.16-1.48, P < 0.00001; recessive: OR = 1.29, 95 % CI = 1.11-1.50, P = 0.0009). In the subgroup of tumor sites, significant associations were also observed in esophageal cancer and colorectal cancer under both genetic models. For MMP2 nt-1306, CT or TT carriers performed significant protection against digestive cancer in the dominant model (OR = 0.69, 95 % CI = 0.55-0.85, P = 0.0007) of the overall. In the subgroup analysis, significant association was found in esophageal cancer, with borderline effects in gastric cancer and oral squamous cell carcinoma. For MMP7 -181 A/G, significant association was observed under two genetic models in the overall (dominant: OR = 1.26, 95 % CI = 1.10-1.43, P = 0.0009; recessive: OR = 1.33, 95 % CI = 1.11-1.60, P = 0.002) and in the individual cancer subgroup of esophageal cancer and gastric cancer. For MMP9 -1,562 C/T, a borderline effect was found with digestive cancers in the total and stratified analysis of the colorectal cancer under dominant model. No association was observed in either the overall or subgroup analysis for MMP3 -1,171 5A/6A. CONCLUSIONS: Our meta-analysis demonstrated the fact that polymorphisms in promoter regions of MMP genes might be related to the susceptibility of digestive cancers, with cancer development for MMP1 and MMP7, and a protection against cancer for MMP2 and MMP9. Further evidences with adequate sample sizes need to be conducted.

A novel germline mutation in HOXB13 is associated with prostate cancer risk in Chinese men.

BACKGROUND: A rare mutation G84E in HOXB13 was recently identified to be associated with prostate cancer (PCa) in Caucasians. The goal of this study is to test association between HOXB13 genetic variants and PCa risk in Chinese men. METHODS: All study subjects were part of the Chinese Consortium for Prostate Cancer Genetics (ChinaPCa). In the first stage, we screened for mutations by sequencing the HOXB13 coding region in 96 unrelated PCa patients. In stage 2, G84E and novel mutations found in stage 1 were genotyped in 671 PCa patients and 1,536 controls. In stage 3, mutation status in 751 additional PCa patients was imputed via haplotype. RESULTS: The G84E mutation was not detected in this study. However, a novel mutation, G135E, was identified among 96 patients in stage 1. It was also observed twice in 575 additional PCa patients but not in 1,536 control subjects of stage 2. The frequency of G135E was significantly different between cases and controls, with a P-value of 0.027, based on Fisher's exact test. Haplotype estimation showed that G135E mutation carriers shared a unique haplotype that was not observed in other subjects. In stage 3, two more PCa patients were predicted to carry the G135E mutation. CONCLUSIONS: We identified a novel rare mutation in the HOXB13 gene, G135E, which appears to be a founder mutation. This mutation is associated with increased PCa risk in Chinese men. Consistent with a previous report, our findings provide further evidence that rare mutations in HOXB13 contribute to PCa risk.

Serum major-histocompatibility-complex class I-related chain A antibody detection for the evaluation of graft dysfunction in renal allograft recipients.

BACKGROUND: In addition to the well-known antibodies against human leukocyte antigens (HLA)-induced kidney-graft rejection, polymorphic major-histocompatibility-complex (MHC) class I-related chain A (MICA) antigens can elicit antibodies and have been suggested to play a role in the antibody-mediated allograft rejection (AMR). We carried out a prospective study of MICA antibodies in post-renal transplant patients to determine the association between MICA antibodies, C4d staining, histological features, and graft outcome. METHODS: We tested 52 patients who had biopsy results due to graft dysfunction. The MICA antibodies in concurrent sera were determined by Luminex. All patients were followed up for one year after renal biopsy. The influence of antibody production on the function of graft was analyzed. RESULTS: Antibodies against MICA were positive in 15 out of the 52 patients (28.9%). The presence of MICA antibodies was associated with renal-allograft deterioration. During one-year follow-up, the estimated glomerular filtration rate (eGFR) decreased (24.0 ± 3.4)% among recipients with anti-MICA antibodies. However, among recipients without anti-MICA antibodies, the eGFR has declined only (8.4 ± 3.0)% (P = 0.017). The association between C4d staining, histological features and MICA antibody production was found no significant difference. CONCLUSION: Besides anti-HLA antibodies, the presence of post-transplant MICA antibody is associated with poor graft outcome and increases the risk of graft failure.